Update import paths for isEqualEs6 in immer-utils and related tests to include the full file path.

Author: flexsurfer

src/immer-utils.ts

@@ -6,7 +6,7 @@
 import { isDraft, original as immerOriginal, current as immerCurrent, enableMapSet as immerEnableMapSet } from 'immer';
 import { setGlobalEqualityCheck, getGlobalEqualityCheck } from './settings';
 import isEqual from 'fast-deep-equal';
-import isEqualEs6 from 'fast-deep-equal/es6';
+import isEqualEs6 from 'fast-deep-equal/es6/index.js';
 
 /**
  * Safe version of immer's original function

src/tests/immer-utils.test.ts

@@ -1,7 +1,7 @@
 import { enableMapSet, original, current } from '../immer-utils';
 import { getGlobalEqualityCheck, setGlobalEqualityCheck } from '../settings';
 import isEqual from 'fast-deep-equal';
-import isEqualEs6 from 'fast-deep-equal/es6';
+import isEqualEs6 from 'fast-deep-equal/es6/index.js';
 
 describe('immer-utils', () => {
     describe('enableMapSet', () => {